DURAMAX + ALLISON = 765 LB-FT OF TORQUE[/h][h=3]PROVEN POWER[/h]The new Silverado HD gets its heavy-duty power from proven sources, including the legendary available Duramax® Turbo-Diesel V8 mated to the legendary Allison® 6-speed automatic transmission. With 765 lb-ft of torque under your right foot, it’s a beast of burden. The standard powertrain is our VortecTM 6.0L V8. Want to run LPG/CNG? The 2015 Silverado 2500 will also be available with a VortecTM 6.0L V8 featuring hardened valve seats to allow the use of SFI Compressed Natural Gas.